I would guess, battle.net could just look at youre computers MAC address or something uniquely identifying your network or computer and ban that cd key.
only way around that, is to spoof your mac, or something like that, or use a different cpu to play d2 on. its going to be hard without a vpn but you could try
tethering youre cell phone for internet access as d2 uses little data.
This post was edited by Trithalas on Jul 9 2019 08:44pm